1. Field of the Invention
The present invention relates to a process for the continuous production of rubber compounds with a twin-screw extruder.
2. Description of Related Art
DE 37 29 237 discloses a process in which rubber, together with fillers, oils, auxiliary substances, and crosslinking agents, is continuously converted into a rubber compound in a twin-screw extruder. Crushed rubber is fed into the extruder together with a processing aid, and masticated along a first screw section. At the end of this first screw section, the entire amount of filler, including carbon black and plasticizing oils, as well as other auxiliary substances and crosslinking agents well known in the art, are introduced into the extrudate, which has a temperature of approximately 60.degree. C. to 80.degree. C. in this zone. These components are mixed in the second extruder section with the rubber before the resulting compound is homogenized in a third extruder section.
Mixing carried out according to this process is satisfactory although a comparatively lengthy homogenizing phase was necessary. A high specific energy requirement was necessary, however, for production of the rubber compound.